I'm pretty sure to parallel one shunt regulator for both channels (L and R) is really bad idea, because of too strong crostalk between channels via same PSU source.
Even with white cathode follower which has strong PSRR, it is not good idea.
Your schematic however is symetrical totem pole amp, which has medium PSRR value.

Can I make Paypal transfer for 3 PCB in amount 3x30 USD, or I need to wait some options for postage cost?

Concerning gabanyayaya SRPP schematic - it shows like I/V ala Lampizator with 6N2P - one solution for I/V, amp and even buffer. If here is question of space in box, it is not worst solution, IMHO.
What is wrong with SRPP as I/V - can you share your experience?

gabanyayaya

Indeed you can use one shunt regulator as power suplly, but better substitute by it only diodes D1-D4 - leaving RC filters separate for L and R channels. This would be reasonable because even SRPP's upper tube works as CCS, this is true only if SRPP designed well - matched on specific Rload.
You can read about it here - The Tube CAD Journal,SRPP Decoded .

If you need to calculate SRPP, just please write me - s.navikas@zebra.lt, I will do it with TubeCAD for my pleasure.

SRPP sounds awful in a DAC, it is very load dependant. Just use a low Rp high gain tube in bypassed cathode with output from the anode. Use 6n6p or 5842 (for more gain), sounds much better than a SRPP, trust me I've tried many tube DAC stages.

Hi everyone. Current everything I was ready to submit designs for manufacturers to make circuits.

So you have registered, please let me transfer the funds to my order soon.

Time to receive funding to start from today to 16-3-2010
When I receiving funding will be made immediately,
on the 22-3 production was finished 2 – 4 - 2010
Then I will send the first day for all of you!